Senate Minority Leader Mitch McConnell has bought six figures worth of airtime to back a television ad campaign beginning on Thursday. The buy marks the start of what could be one of the cycle's most contentious races.

McConnell's ads, up a year and eight months before his name appears on a general election ballot, will air for a week in the Lexington, Ky., and Louisville, Ky., media markets. The buy is in the "low six figures," a McConnell aide told CQ Roll Call.

Democrats framed the early ad buy as a sign of weakness.

“Running campaign commercials almost two years before an election is an unprecedented admission of fear for a sitting senator," Dan Logsdon, the chairman of the state Democratic Party, said in a statement.

Recent polls show McConnell in a less-than-desirable position. But he is seeking re-election as a Republican in a state that traditionally elects GOP candidates in federal races.

What's more, McConnell begins his 2014 campaign with a significant monetary advantage over any potential challenger. At the end of 2012, McConnell's campaign had $7.4 million in the bank.